The 3 buttons at the top of the results serve a dual purpose: 1. They are sorting buttons (recommendation score, time to destination and price); 2. They provide a quick overview of the results in terms of price and flight times.  In some cases, you will notice big differences in prices and flight duration between the different buttons.

Notice that flight duration is calculated as an average per direction for round trip flights and total flight time for the entire route in cases of multi-destination routes. 

Important Note: These times, as well as the prices, are calculated from the visible results and change when you filter your results.